1. Field of the Invention
The present invention relates to an electronic device having a function of selecting from among a plurality of operating modes that differ in power consumption, and a power control method.
2. Description of the Related Art
Recently, electronic devices such as multimedia-capable personal computers, game machines and audiovisual devices have been developed. Attention has been given to a home network device for combining these electronic devices using a home network device and storing data, especially stream data such as broadcast program data in the home network device.
The home network device employs a high-performance processor because it needs to fulfill a router function of network routing, a file server function, and a function of receiving and processing stream data for broadcast. Thus, the home network device increases in power consumption even when it is idle. The home network device is energized at all times and thus its thermal design or cooling fan's noise cannot be ignored.
In view of the above, a technique of effectively suppressing power consumption is desired in electronic devices such as home network devices.
Various power-saving techniques have conventionally been proposed. For example, Jpn. Pat. Appln. KOKAI Publication No. 11-327706 discloses a device in which an electronic circuit is divided into a plurality of circuit blocks and power is selectively supplied to one of the circuit blocks necessary for operating in different system modes.
However, the conventional power-saving techniques are not directed to an electronic device such as a home network device. A fine power control is not therefore performed, paying attention to power consumption in a circuit block that performs a process associated with network routing and a circuit block that processes audiovisual (AV) data, i.e., receives stream data. The conventional techniques cannot decrease power consumption sufficiently in an electronic device such as a home network device.
Therefore, there is a need to provide an electronic device capable of effectively suppressing power consumption due to that of high power circuit blocks, and a power control method.